JPH06236598A - Braking mechanism of reel base - Google Patents

Abstract

PURPOSE:To impart proper back tension to a tape at the time of taking up the tape and to attain miniaturization and low power consumption of the mechanism by projectively providing a brake pawl capable of engaging with a reel gear at one end of an oscillating idler lever. CONSTITUTION:An idler gear 7 is rotated clockwise at the time of REW and REV, so that the oscillating idler lever 5 is turned counterclockwise, and the idler gear 7 and the reel gear 34 of an S-side reel base 3 are intermeshed with each other. Consequently, the reel gear 34 is turned counterclockwise to take up the tape T. In other words, since the S-side reel base 3 is not braked, the reel gear 34 of the reel base, a reel plate 32 and a reel wing 33 are integrally rotated to take up the tape T. A T-side reel base 4 is pulled by the tape, and a reel wing 43 and a reel plate 42 are rotated counterclockwise. Then, since the reel gear 44 is engaged with the brake pawl 52 of the idler lever 5, and hence unrotatable, slip force is generated to impart back tension to the tape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reel base brake mechanism for a magnetic recording / reproducing apparatus such as a VTR or DAT.

[0002]

2. Description of the Related Art Miniaturization of magnetic recording / reproducing devices such as VTRs and DATs has progressed, and a reel stand brake mechanism for applying back tension to the tape during winding of the tape has been devised for miniaturization. ing. FIG. 7 shows an example of a reel stand brake mechanism using a one-way clutch (Japanese Patent Laid-Open No. 64-86351).

This is a take-up reel stand (4) (hereinafter T
One-way clutch on the reel gear (44) of the side reel stand)
The gear (91) of (9) is always meshed. The gear (91) of the one-way clutch is locked in the clockwise direction and does not rotate, and can rotate only in the counterclockwise direction. Therefore, the reel gear (4
4) can rotate clockwise, but cannot rotate counterclockwise.

As shown in FIG. 3, the T-side reel stand (4) has a felt (4) between the reel gear (44) and the reel plate (42).
5) and the reel gear (4
A slip mechanism (40) that generates a certain slip force is configured between the reel plate (42) and the reel plate (42). A reel wing (43) that rotates integrally with the reel plate is provided on the upper portion of the reel plate (42) so that the reel wing engages with a reel (not shown) of the cassette tape to wind the tape. to enable.

As shown in FIG. 7, when the reel bases (3) and (4) are driven, a transmission force from a motor (not shown) is applied to the drive gear (6).
Is transmitted to the idler gear (7) via the
(3) (hereinafter referred to as the S-side reel stand) or the reel gear (44) of the T-side reel stand (4). Idler gear (7) and idler lever
A slip mechanism (not shown) is interposed between the idler gear (7) and the idler gear (7) when the idler gear (7) rotates clockwise when the idler gear (7) rotates clockwise. The reel gear (34) of the side reel stand (3) meshes.

When the idler gear (7) rotates counterclockwise, the idler lever (5) rotates clockwise, and the idler gear (7) meshes with the reel gear (44) of the T-side reel stand (4). In each of the PLAY, REC, FF, and CUE modes, the T-side reel stand (4) serves as the drive side and winds the tape. At this time, the one-way clutch (9) rotates counterclockwise so that the reel gear (44) and the reel plate (4) can rotate.
2) rotates together.

In each of the REW and REV modes, the S-side reel stand (3) serves as the driving side, winds the tape, and rewinds the tape on the reel stand. At this time, the T-side reel base (4) is rotated counterclockwise by the tape T, but the reel gear (44) meshing with the gear (91) of the one-way clutch (9) that does not rotate clockwise is I can't rotate. Therefore reel gear (44)
A slip occurs between the reel plate (42) and the reel plate (42), which serves as a braking force, and serves to give the tape T an appropriate back tension. In the mode in which the T side reel stand (4) is on the drive side, another brake mechanism is attached to the S side reel stand.
(Not shown) is designed to work.

[0008]

Although the use of the one-way clutch is advantageous for downsizing the mechanism, the structure of the one-way clutch becomes complicated, so that the number of constituent parts is increased and the assembling workability is poor. In addition, since a slight loss torque is generated even in the rotatable direction of the one-way clutch, there is a problem that, for example, in the PLAY mode, the T-side reel stand is always loaded with a load and power consumption increases. . The present invention clarifies a reel base brake mechanism that solves the above problems.

[0009]

In the reel stand brake mechanism of the present invention, a swing idler lever (5) is provided between the supply side reel stand (3) and the winding side reel stand (4), and the lever ( 5) Selectively rotate the idler gear (7) provided at the free end of the lever (5) to the reel gear (34) (44) of the supply side reel stand (3) or the winding side reel stand (4). The reel plate (3) is engaged through the slip mechanism (30) (40) provided on the reel stand.
2) In the reel stand brake mechanism that rotationally drives (42), the swing idler lever (5) is engaged with the reel gear on the opposite side of the reel gear with which the idler gear (7) meshes to rotate the gear. It has brake pawls (52) to prevent it.

[0010]

[Operation and effect] The brake claw (52) engages with the reel gear of the reel stand on the opposite side of the reel stand on which the idler gear (7) on the swing idler lever (5) meshes, and the reel gear rotates. Prevent. Therefore, a slip force is generated between the reel gear and the reel plate to apply an appropriate back tension to the tape and prevent the tape from loosening.
The brake mechanism of the present invention has a simple structure in which the brake claw (52) is provided on the idler lever (5) so that the REW,
In the REV mode, an appropriate back tension can be applied to the tape, and in the PLAY, REC, FF, and CUE modes, the tape can be rotated without applying an extra load to the T-side reel stand. As a result, downsizing, cost reduction, and low power consumption can be achieved.

[0011]

EXAMPLE As shown in FIG. 1, a head cylinder (11), a capstan (12), an S side reel stand (3) and a T side reel stand (4) are arranged on a chassis (1) in a known manner. A swing idler lever (5) is provided between the S-side reel stand (3) and the T-side reel stand (4). Idler lever (5) is the chassis
It is pivotally supported by a support shaft (8) protruding from (1), and a transmission force from a motor (not shown) is transmitted to the support shaft (8) between the chassis (1) and the idler lever (5). The drive gear (6) through which the power is transmitted is fitted.

A drive gear is provided on the tip side of the idler lever (5).
An idler gear (7) meshing with (6) is pivotally supported by a pivot shaft (72). A slip mechanism (70) is provided between the idler gear (7) and the idler lever (5), and the slip mechanism includes a graphite nylon seat plate (71) between the idler gear (7) and the idler lever (5). Interposer, idler lever (5)
The idler lever (5) is provided with a leaf spring portion (51) so that a slight load can be applied in the thrust direction in order to generate a slip force necessary for the rotation operation of the.

When the idler gear (7) rotates clockwise, that is, when the drive gear (6) rotates counterclockwise, the idler lever (7) rotates.
(5) rotates counterclockwise around the support shaft (8), and when the idler gear (7) rotates counterclockwise, that is, when the drive gear (6) rotates clockwise, the idler lever (5) Rotates clockwise.

A feature of the present invention is that a brake pawl (52) engageable with a reel gear (44) of a reel stand, which will be described later, is provided at one end of the idler lever (5) in a protruding manner. In the embodiment shown in FIG. 1, when the swing idler lever (5) is rotated toward the S side reel stand (3), the pawl engages with the reel gear (44) of the T side reel stand (4).
(52) is provided.

As shown in FIG. 3, the S-side reel stand (3) and the T-side reel stand (4) have the same structure, and the reel stand body (31) (4).
1) reel plate (32) (42) and reel wing (33)
(43) is provided in a protruding manner, and reel gears (34), (44) are rotatably provided.

Reel gears (34) (44) and reel plate (32)
A slip mechanism (30) (40) is provided between (42), and the slip mechanism includes a reel gear (34) (44) and a reel plate (3).
2) Felt (35) (45) is inserted between (42) and spring (36) (46)
The reel gears (34) (44) and reel plate
It is configured such that a constant slip force is generated between (32) and (42). The reel wings (33) (43) are the parts that fit with the reels of the cassette tape, and the reel plate (32)
It rotates together with (44).

FIG. 1 shows the operating state of the brake mechanism during REW and REV. Since the idler gear (7) rotates clockwise, the idler lever (5) rotates counterclockwise, and the idler gear (7) meshes with the reel gear (34) of the S-side reel stand (3). As a result, the reel gear (34) of the S-side reel stand (3) rotates counterclockwise to wind up the tape T. The reel gear (44) of the T-side reel stand (4) is prevented from rotating by the brake claw (52) of the idler lever (5) being engaged. The chassis (1) is provided with a pin (10) protruding from the idler gear (7) for restricting the rotation range of the idler lever (5).
Unnecessary biting of the reel gears (34) (44) is prevented.

However, in the state of FIG. 1, since the brake is not applied to the S side reel stand (3), the reel gear (34), the reel plate (32) and the reel wing of the reel stand.
(33) rotates integrally and winds the tape T. The T-side reel stand (4) is pulled by the tape, and the reel wing (43),
The reel plate (42) rotates counterclockwise, but the reel gear (44) cannot rotate because the brake claw (52) of the idler lever (5) is engaged, which causes slip force, which causes back tension on the tape. Is given.

FIG. 4 shows PLAY, REC, FF, CUE.
The braking operation state at the time is shown. Idler gear (7)
Rotates counterclockwise, the idler lever (5) rotates clockwise, and the idler gear (7) and the T-side reel stand (4)
Mesh with the reel gear (44). Since the brake claw (52) of the idler lever (5) is separated from the reel gear (44),
The reel gear (44) can rotate clockwise with no load.
At this time, the S-side reel stand (3) is operated by another brake mechanism (not shown) for giving back tension to the tape T.

In FIG. 5, the idler gear (7) is on the T side reel stand.
When meshed with (4), reel gear (3
4) shows another embodiment of the brake device configured so that the brake claw (52) of the idler lever (5) is engaged.
Is the reel gear (34) for both the S side and T side reel stands (3) (4)
Another embodiment is shown in which two brake pawls (52) are provided on the idler lever (5) so that the brake pawls (52) are alternately bitten into (44). The present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a plan view showing a state where a brake is applied to a T-side reel stand.

FIG. 2 is an explanatory view of mounting a swing idler lever.

FIG. 3 is a sectional view of a reel stand.

FIG. 4 is a plan view of a tape wound on a T-side reel stand.

FIG. 5 is a plan view of another embodiment.

FIG. 6 is a plan view of another embodiment.

FIG. 7 is a plan view of a conventional example.

[Explanation of symbols]

 (3) Supply side reel stand (4) Winding side reel stand (5) Swing idler lever (7) Idler gear (52) Brake claw

Claims (1)

[Claims] 1. A supply side reel stand (3) and a winding side reel stand
A swinging idler lever (5) is provided between the idler gear (7) and the idler gear (7) provided at the free end of the lever (5) by selectively rotating the lever (5). (3) Or meshes with the reel gears (34) (44) of the take-up reel stand (4), and the reel plates (32) (42) are attached via the slip mechanisms (30) (40) provided on the reel stand. In the rotating reel base brake mechanism, the idler lever (5) has an idler gear.
A reel stand brake mechanism including a brake claw (52) that engages with a reel gear on the opposite side of the reel gear with which (7) meshes to prevent rotation of the gear.